Science has now proved what kindergarten teachers, reality-show fans and Catholic priests discover anew every day: humans can’t help talking about themselves. It just feels too good.

In a new study [PDF] published in the respected Proceedings of the National Academy of Sciences, Harvard University researchers conducted a series of experiments to assess how much people liked talking about themselves and why. In one study, they scanned people’s brains while those people either revealed personal information about themselves or judged the personalities or opinions of others. In another experiment, researchers tested whether people preferred to answer questions about themselves, other people or neutral facts — participants got differing levels of monetary compensation depending on the question they chose. Yet another study explored whether people wanted to share their answers with others or keep them to themselves.

No matter the test, the researchers, led by Diana I. Tamir and Jason P. Mitchell at Harvard’s psychology department, found the results pointed the same way: humans get a biochemical buzz from self-disclosure.

That’s why we spend almost 40% of conversation talking about ourselves, says the study — our brain chemistry drives us do it. In the experiment in which participants talked about either themselves or others during an fMRI scan, researchers found that sharing personal information led to activity in the reward areas of the brain — the same ones that are engaged in response to rewards like sex and food. Talking about other people did not trigger the circuits as much.

In the study in which researchers offered people tiny amounts of money (between 1¢ and 4¢) for answering questions about themselves or others, people were willing to forgo 17% of their earnings in order to answer questions about themselves. When the payoff was equal, people chose to talk about themselves two-thirds of the time.

The researchers noted that people particularly enjoyed self-disclosure if they knew other people were listening. When people were given a choice to share their responses with others or to keep them private, they gave up 25% of their potential earnings in order to broadcast the personal info. “[The] effects were magniﬁed by knowledge that one’s thoughts would be communicated to another person, suggesting that individuals ﬁnd opportunities to disclose their own thoughts to others to be especially rewarding,” says the study. All of this goes along way toward explaining the appeal not just of inherently self-promoting social-media platforms like Facebook and Twitter but also of talk radio, Jerry Springer and even book groups.

Previously, humans’ penchant for banging on about No. 1 was thought to be caused by a desire for intimacy with others, a way to open up to people and get them to trust us in return in hopes of setting the foundation for friendship. But this appears to be the first study to suggest that people bang on about themselves mainly because they like the way it feels.

So the next time you’re stuck at a party with a bore who can’t stop talking about his or her opinions on dry aged cheddar, remember, it’s all about brain chemistry. If it gets really bad, try talking about yourself instead. Might take the edge off.